1. Field of the Invention
This invention relates to a used master disposing apparatus for compressing a used sheet-like master to discard it, and more particularly to a used master disposing apparatus in which a used mimeographic stencil discharged from a mimeographic printing machine is compressed and discarded.
2. Description of the Related Art
FIG. 15 of the accompanying drawings is a perspective view showing a used stencil discharging apparatus of a mimeographic printing machine. In FIG. 15, reference numeral 1 designates a receptacle box for receiving used stencils, the receptacle box 1 having at the front an inlet 2 and at one side an outlet 3.
A drive shaft 5 supporting a plurality of gears 4, and rubber rollers 6 are disposed at the inlet 2 of the receptacle box 1 in parallel relation to the axis of a non-illustrated master drum. The respective gears 4 and the respective rubber rollers 6 are in engagement with each other; a used stencil S removed from the master drum is thereby brought into the receptacle box 1 as the drive shaft 5 is driven for counterclockwise rotation in FIG. 15 by a non-illustrated motor.
At the outlet 3 of the receptacle box 1, coacting metallic and rubber rollers 7, 8 are disposed in parallel relation to the axis of the master drum. The metallic roller 7 and the rubber roller 8 coact to discharge the stencil from the receptacle box 1.
On the bottom of the receptacle box 1, a plurality of metallic follower feed rollers 10 is arranged at small distances in parallel relation to the metallic and rubber rollers 7, 8. Each follower feed roller 10 is rotatable about its shaft 11.
A drive feed roller 14 is rotatably supported on the top (ceiling) of the receptacle by a shaft 13 parallel to the shaft 11, and is driven in clockwise direction by a non-illustrated motor. The drive feed roller 14 has a semicylindrical contour. The semicylindrical peripheral surface is covered with an elastic member 15 which is elastic like a sponge or formed of a synthetic resin and has a high coefficient in friction. The drive feed roller 14, in the illustrated conventional example, has a central gap 16 dividing the semicylindrical roller in two halves axially. The ceiling wall of the receptacle box 1 has a pair of openings 17, 17 receptive of the divided drive feed roller 14, leaving a bridge 18 between the two openings 17, 17 to prevent the stencil from being wound around the peripheral surface of the drive feed roller 14.
There is defined in the receptacle box 1 between the drive feed roller 14 and the follower feed roller 10 a gap receptive of the stencil when the omitted half of the drive feed roller 14 is located in a position confronting the follower feed roller 10. To the contrary, the other half, i.e. the elastic member 15 of the drive feed roller 14 comes in pressing engagement with the follower feed roller 10 when the elastic member 15 of the drive feed roller 14 faces the roller 10.
A disposal box 19 extends downwardly from and communicates with the outlet 3.
With the foregoing arrangement, the stencil S removed from the non-illustrated master drum is discharged into the receptacle box 1 by the gears 4 and the rubber rollers 6. The stencil S discharged in the receptacle box 1 assumes a folded posture longitudinally bent in a wavy shape as its movement is restricted by the wall surfaces of the receptacle 1. At that time, since the omitted half of the drive feed roller 14 faces the follower feed roller 10 to define therebetween a space for receiving the stencil S, the stencil S is discharged into the receptacle box 1 without interference by the drive feed roller 14. In the meantime, a part of the stencil S is inserted between the follower feed roller 10 and the drive feed roller 14.
When the entire stencil S has been discharged in the receptacle box 1, the drive feed roller 14 is driven in the clockwise direction in FIG. 15 so that the elastic member 15 of the drive feed roller 14 can be rotated to engage the follower feed roller 10. As the stencil S is compressed between the follower feed roller 10 and the drive feed roller 14, the stencil S is longitudinally folded and is conveyed in the receptacle box 1 toward the outlet 3 by the frictional resistance with the elastic member 15. The stencil S having been folded by compressing is relatively hard and is sandwiched between the metallic and rubber rollers 7, 8 and is thus discharged from the output 3 into the disposal box 19.
Although the stencil or master discharged in the disposal box 19 by the stencil discharging apparatus assumes a folded posture, it is considerably bulky. Consequently it is impossible to accommodate a large quantity of used masters in the disposal box 19 by merely dropping thereinto so that the disposal box 19 would be soon filled with the stencils.
When the receptacle box filled with the stencils is removed from the apparatus, the stencils in the receptacle box become bulky due to their restoration as the top of the stencil stack is freed upon removal of the receptacle box, causing some upper stencils to overflow from the receptacle box.